usb: phy: isp1301: fix non-OF device reference imbalance

commit b4b64fda4d30a83a7f00e92a0c8a1d47699609f3 upstream.

A recent change fixing a device reference leak in a UDC driver
introduced a potential use-after-free in the non-OF case as the
isp1301_get_client() helper only increases the reference count for the
returned I2C device in the OF case.

Increment the reference count also for non-OF so that the caller can
decrement it unconditionally.

Note that this is inherently racy just as using the returned I2C device
is since nothing is preventing the PHY driver from being unbound while
in use.

Fixes: c84117912bdd ("USB: lpc32xx_udc: Fix error handling in probe")
Cc: stable@vger.kernel.org
Cc: Ma Ke <make24@iscas.ac.cn>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://patch.msgid.link/20251218153519.19453-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/phy/phy-isp1301.c b/drivers/usb/phy/phy-isp1301.c
index ad3d57f1c273cf1db9667562096d712e55e5b84c..f60f8ab5a89f14edf8dd2668474eb83bddf49e0a 100644 (file)
--- a/drivers/usb/phy/phy-isp1301.c
+++ b/drivers/usb/phy/phy-isp1301.c
@@ -152,7 +152,12 @@ struct i2c_client *isp1301_get_client(struct device_node *node)
                return client;
 
        /* non-DT: only one ISP1301 chip supported */
-       return isp1301_i2c_client;
+       if (isp1301_i2c_client) {
+               get_device(&isp1301_i2c_client->dev);
+               return isp1301_i2c_client;
+       }
+
+       return NULL;
 }
 EXPORT_SYMBOL_GPL(isp1301_get_client);